Looking for logging into the Raspberry Pi Serial Port site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Raspberry Pi Serial Port site. After that you can login as usual with your login credentials.
https://elinux.org/RPi_Serial_Connection
http://www.netzmafia.de/skripten/hardware/RasPi/RasPi_Serial.html
https://www.instructables.com/id/Read-and-write-from-serial-port-with-Raspberry-Pi/
http://www.hobbytronics.co.uk/raspberry-pi-serial-port
https://spellfoundry.com/2016/05/29/configuring-gpio-serial-port-raspbian-jessie-including-pi-3/
https://www.raspberrypi.org/forums/viewtopic.php?t=195976
https://www.raspberrypi.org/documentation/configuration/uart.md
https://cdn-learn.adafruit.com/downloads/pdf/adafruits-raspberry-pi-lesson-5-using-a-console-cable.pdf
https://raspberrypi.stackexchange.com/questions/45570/how-do-i-make-serial-work-on-the-raspberry-pi3-pi3b-pizerow
https://pimylifeup.com/raspberry-pi-serial/
https://learn.adafruit.com/adafruits-raspberry-pi-lesson-5-using-a-console-cable/enabling-serial-console
https://www.circuits.dk/setup-raspberry-pi-3-gpio-uart/
https://hallard.me/enable-serial-port-on-raspberry-pi/